Rotary reamer for oil, gas, and other wells



Nov. 17, 1936.

E. BIGLER 2,061,057

ROTARY REAMER FOR OIL, GAS, AND OTHER WELLS 7 FIG; i.

I N VEN TOR. I BY fiyqz/ Filed Feb. 21, 1936 ATTORNEYS.

Patented Nov. 17, 1936 UNITED STATES ROTARY REAMER FOR OIL, GAS, AND OTHER WELLS Eugene Bigler, Oklahoma City, Okla, assignor to T. Myron Pyle, trustee Application February 21, 1936, Serial No. 65,086

2 Claims.

My invention relates to improvements in rotary reamer having built into it the function of a jar as now used only in standard drilling.

The principal objects of my invention are to 5 provide a device of this character which is positive in action, simple and inexpensive in construction; new, novel and easily operated; which is strong, durable, reliable and of evident utility; which cannot easily get out of order and. is eflicient for the purposes for which it is intended; to provide single or double three-point rotary reamers with triangular shape, full streamlined blocks mounted upon a hollow, angular shaft and 'adapted for vertical reciprocation on said shaft; to provide strong helical spring or springs to hold said blocks normally in fixed positions but allow vertical movement on the said shaft; to provide jar means for dislodging reamer and cutters when stuck in the hole; to provide upward pressure means whereby the reamer will cut upwardly against any material which might prevent the removal of the reamer from the hole.

With these and other objects in View my invention consists of the construction, novel feature and combination of parts hereinafter more fully described, illustrated in the accompanying onesheet drawing and pointed out in the claims hereto appended. Various changes in the form, proportion, size, shape, weight and minor details of construction, within the scope of my invention may be resorted to without departing from the spirit or broad principle of my invention as set forth in the appended claims or sacrificing any of the advantages thereof.

In the accompanying drawing, Figure I is a fragmentary elevation, partly in section; Figure II is a section on the line 2--2 of Fig. I and Figure III is an elevation showing the spring in compressed position.

In the following description like characters of reference designate like parts in all the figures, and it is to be understood that the drawing is to be interpreted as being illustrative and not restrictive.

The inherent novelty of my improved reamer resides in its ability to cut in the reverse or opposite direction from those now in use. The ordinary reamer operates entirely from downward pressure exerted from above and cuts only as the hole is deepened. The ream is usually forged from a single piece of steel and has one or more enlargements or blocks into which are fitted a plurality of rotating cutters. In my improved reamer I make this enlargement, not integral with the reamer body but as a separate unit, of

which I may use one or a plurality, for mounting the cutters. These cutter blocks are made with an angular central opening, for seating upon a corresponding shaped hollow shaft. The drawing shows this opening and shaft as hexagonal but other shapes may be employed. When mounted upon the shaft the said blocks have vertical reciprocation thereon and constitute a floating unit. The said blocks are held in place at the top of the hollow shaft by a helical spring of sufiicient compressive strength to exert a uniform upward pressure. This pressure is suificient to cause the cutters to operate against any obstruction, constriction, or caving in the hole above the reamer, when the reamer is rotated and subjected toa slight upward pull suflicient to compress the helical spring. When it becomes necessary to pull the drill stem and string of tools from the hole and the said stem is stuck and refuses to move upward even when the traveling block and cable exerts an enormous pull, the invariable cause is found to be at the reamers. Since the reamers follow the drilling tools and enlarge the hole, they seat snugly therein but due to the whipping action of the long flexible drill stem the bore of the hole is plastered with drilling mud mixed with cuttings loosened by the drill bit. This plastering material constricts the hole and hardens to the consistency of concrete above the reamers. At present the only way to remove the reamers is by a straight upward pull of the dead weight of thousands of feet of drill pipe in the deep wells. This often causes the wrecking of the crown block, and collapse of the derrick with possibly the loss of life. So far it has proved impractical to pull the reamer upwardly against the obstruction or constriction and successfully rotate the said reamer at the same time, mainly on account of the impossibility of applying even pressure against the said obstruction. My improved device obviates this as the helical spring supplies sufficient, even, upward cutting pressure while the cutters are rotated by the machinery at the mouth of the well.

As can be readily understood from a study of the drawing, the amount of vertical play between the extended and fully compressed position of the helical spring permits my device to be used as a jar, enabling the cutting blocks to be jarred down and thus permitting the free working of the device for cutting upward, thereby releasing any strain or pull on the crown block and top of the derrick.

One embodiment of my invention is shown as follows: Hollow stem 1 is screwed into the box of rotary substitute 2 at the top and rotary substitute 3 at the bottom, the said substitutes being set into the line of drilling stem 4 where needed. Helical spring 5, being rectangular in section, is seatedon top of substitute 3 and envelopes the said stern l. Cutter block 6 is seated against the under edge of substitute 2 and on top of cutter block I, which rests on the upper end of helical spring 5. The said blocks 6 and l are provided with central angular openings which conform to the shape of hollow stem l and permit vertical reciprocation thereon. Each block has three reamer cutters 8, those on block 6 being staggered with reference to those on block 1, thus constituting a double three-point reamer. The cutters rotate on bearing pins 9 which are held in place by set screws it. Arcuate fluid passages ll forming recesses in the said blocks, assures free circulation of drilling fluid upward past the said blocks and bore ii in the hollow stem l is a continuation of the fluid passage of drill stem 4.

When the well bore 13 becomes constricted above block 6 at [4 so that the reamer can not be withdrawn without wrecking the derrick, drill stem 4 is raised until helical spring 5 is fully compressed as can best be seen in Fig. 3. The said stem 5 is locked to the rotary table by means of slips and rotated as in ordinary drilling. Cutters 8, urged upwardly against obstruction M by the powerful, even, uniform pressure of helical spring 5 will cut upward until the said spring 5 is in extended position. Stem 4 can again be raised and locked to the rotary table and this operation continued until the reamer has cut upward past the obstruction and the string of drill pipe and tools can be removed from the well.

Hollow stem l and spring 5 may be made of any desired length. The outer diameter of the said spring 5 conforms approximately to that of the drill pipe 4. When it is necessary to remove cutter blocks 6 and l and spring 5 from the said stem I, said blocks 5 and I may be forced apart sufiiciently to admit a wrench between them for holding said stem while rotary substitute 2 is disconnected. New cutters 8 may be inserted to replace those worn out by removing set screws l0, and driving bearing pins 9 either up or down, as the said pins are so positioned that there is no obstruction to their removal in either direction.

Having thus described my improved reamer, what I claim as new and desire to secure by Letters Patent is:

1. In a device of the class described, an angular, hollow stem connected at both ends to rotary substitutes of greater exterior diameter than the stem, said stem having a longitudinal central bore which conforms to the fluid passage of the drill pipe of which the said hollow stem forms a unitary part, a plurality of cutter blocks having angular, longitudinal openings conforming to that of the said angular, hollow stem and adapted for vertical reciprocation on the said stern, cutters on said blocks a helical spring, rectangular in cross section, seated on and enveloping the said hollow stem between the lower of the said cutter blocks and lower of the said rotary substitutes.

2. In a device of the class described the combination of an angular, hollow stem, rotary substitutes of greater exterior diameter than the stem connected at both the upper and lower ends of said hollow stem, cutter blocks having longitudinal central angular openings conforming to said angular stem and slidably mounted for vertical reciprocation on the said stern, rotary reamer cutters in said blocks, the said cutters of one block being staggered with reference to the cutters of the other of said blocks, a helical spring, having a rectangular cross section, enveloping said hollow stem and seated between the lower of said cutter blocks and the lower of said rotary substitutes, the relative vertical movement of said cutter blocks on the said hollow stem between the extended and compressed positions of said spring being sufficient to jar the said cutter blocks loose when stuck in the bore of the well.

EUGENE BIGLER. 

